Scientific: Tecoma fulva subsp. guarume (synonym Tecoma alata)
Common: orange bells, orange trumpet flower, cahauto
Family: Bignoniaceae
Origin: Peru and northern Chile

Pronounciation: Ta-CO-ma FUL-av

Hardiness zones
11-13, 16, 18-28
USDA 8-11 (more cold tolerant than T. stans)

Landscape Use: Used similarly to T. stans as a medium to large floral accent shrub, background screen, specimen around large patios and ramadas exemplifying regional or Spanish architecture; best used in oasis and transition landscape designs settings, moderately attracts hummingbirds.

Form & Character: Evergreen large shrub, upright and open, stiff and rigid, festive, informal, subtropical to tropical. Though evergreen, winter is a time of quiescence for orange bells.

Growth Habit: Vigorous and upright to 10 to 15 feet in height but can be easily maintained at 5 to 10 feet. It's hardened stems are very brittle and upright developing a crown structure that is more upright and open than T. stans.

Foliage/texture: Opposite, pinnately compound leaves on brownish gray stems, leaflets coarsely serrate, stem lenticels and auxiliary dormant buds are obvious; medium texture.

Flowers & fruits: Orange trumpet flowers in terminal clusters; long, narrow, unsightly light brown bean pods.

Seasonal color: Orange flowers during all growing season, heaviest in spring and fall. In Phoenix, orange bells will not flower during winter except if it is planted in a warm sunny south exposure.

Temperature: Heat loving, but freeze sensitive. In climates colder than Phoenix, orange bells will freeze to the ground every winter. In Phoenix, orange bells will have freeze damage to leaves and small terminal stems most winters, but recovers quickly.

Light: Full sun, partial sun reduces flower frequency and intensity. Grows poorly in shade.

Soil: Tolerant, except high alkalinity will can cause general foliar yellowing.

Watering: Orange bells responds very well to regular water and fertilizer especially during the summer, tolerates only moderate amounts of drought.

Pruning: Prune hard in winter to control height and stiffen upright character.

Propagation: Softwood or semi-hardwood stem cuttings, tissue culture, seed>

Disease and pests: In the Phoenix area, Texas and phytophthora root rot fungi occasionally cause sudden plant death, usually only in heavy soils with a former agricultural use history. During late summer of good monsoon years, a leaf skeletonizer catepillar will ravage foliage on upper stems primarily. The damage to foliage is short lived and cosmetic, not lethal. Several chemical control strategies are available including a biological spray Bacillus thurengensis; however, given the growth habit of Tecoma and its rapid recovery after pruning, I recommend that one strongly head back (prune) infested plants and dispose of the damaged material.

Additional comments: This is an intermediate to large accent shrub for moderately large to large landscape spaces. Orange bells will look sparse during periods of winter cold and high summer heat, as will T. stans.

There exists significant taxonomic confusion with regards to the correct botanical name for orange bells. Do a web search and you can find a veritable cacophony of "correct" scientific names. Tecoma fulva subsp. guaruma (orange bells) is variously recognized as a hybrid between T. stans and T. alata called T. x 'Burnt Out', T. alata 'Orange Jubilee', T. stans 'Orange Jubilee', or as T. x 'Orange Jubilee'. There are many recent cultivated varietal selections, including hybrids cultivars with T. stans. A recent cultivar introduction is Tecoma fulva subsp. guaruma 'Flaming Belles'.

Taxonomic note: There are 14 recognized species of Tecoma, and six recognized subspecies of T. fulva:

  • T. fulva subsp. fulva
  • T. fulva subsp. altoandina
  • T. fulva subsp. arequipensis
  • T. fulva subsp. garrocha
  • T. fulva subsp. guarume
  • T. fulva subsp. tanaeciiflora